Based on the recommendations here on tripadvisor I booked the Dragonback-Tour and was not let down.
Kevin and his colleague picked me up from the hotel and took me to the eastern part of KL. It was a challenging trip mostly because I was not used to the humidity and temperature (we started at 12:00 and climbing at around 13:00 because I could not start earlier) but definitely recommandable for anyone who wants to do something different near KL.
Would do it again anytime!!